BAT 22-Month Source Catalog

All sky map showing classfication of the BAT 22-month survey sources. The figure uses an Aitoff projection in Galactic coordinates;the flux of the source is proportional to the size of the circle. The source type is encoded by the color of the circle.

These web pages present the sources detected in the first 22 months of all sky survey data collected by the BAT coded mask hard X-ray instrument. A complete description of the data and techniques for source detection and analysis can be found in the catalog paper (Tueller et al., ApJS submitted, arXiv:0903.3037).

Abstract

We present the catalog of sources detected in the first 22-months of data from the hard-X-ray survey (14-195 keV) conducted with the BAT coded-mask imager on the Swift satellite. The catalog contains 461 sources identified above the 4.8σ detection threshold with BAT. A total of 262 of the sources are Seyfert galaxies (median redshift z ~ 0.03) or blazars, with the majority of the remaining sources are associated with X-ray binaries in our Galaxy. High angular resolution X-ray data for every source from Swift XRT or archival data have allowed associations to be made with known counterparts in other wavelength bands for over 90% of the detections, including the discovery of ~ 30 galaxies previously unknown as AGN and several Galactic sources. This on-going survey is the first uniform all-sky hard X-ray survey since HEAO-1 in 1977.

Since the publication of the 9-month BAT survey we have increased the number of energy channels from 4 to 8 and have substantially increased the number of sources with accurate average spectra. The BAT 22-month catalog is the the product of the most sensitive all-sky survey in the hard X-ray band, with a detection sensitivity (4.8σ) of 2.2 × 10-11 erg cm-2 s-1 (1 mCrab) over most of the sky in the 14-195 keV band.

Spectra

The source flux from the 22-Month Source Catalog is given for each of the eight survey bands in a pha FITS file. You will also need the Diagonal Response Matrix.

a The BAT names are preferentially the names used to request XRT followup observations (and used in the HEASARC archive). When no previous BAT name for this source exists, we use the BAT position in this catalog.b The BAT source positions listed here are all uniformly generated from a blind search of the 22-month data and are J2000 coordinates.c The counterpart position is the most accurate position known of the object in the 'name' column in J2000 coordinates, and is usually taken from NED or SIMBAD. If no counterpart is known, the blind BAT position is listed.d The flux is extracted from the BAT maps at the position listed for the counterpart, is in units of 10-11ergs s-1 cm-2, and is computed for the 14-195 keV band.e The meaning of the confusion flag is as follows: A = 'Confused' source, B = 'Confusing' source, AB = Both confused and confusing. To make sense of this confounding scenario, see §4 and §4.3.f The hardness ratio is the ratio of the 35-150 keV count rate to the 14-150 keV count rate.g The redshifts are taken from the online databases NED and SIMBAD or in a few cases from our own analysis of the optical data. A blank indicates that the object is Galacatic, and a ? indicates that the object has an unknown redshift.h The luminosity is computed from the flux and redshift in this table, with units of log[ergs s-1] in the 14-195 keV band.